Fault reactivation controlled by overlying strata in underground mining

The collapse modes and evolving stress states of overlying strata during mining operations critically govern the initiation of fault slip. Employing Coulomb stress as the activation criterion, we present a theoretical model that captures the mechanisms of fault reactivation triggered by the instability of fractured overburden. This model delineates the complex interplay between overburden deformation and fault activation, establishing a mechanistic link between strata movement and fault slip. Our results demonstrate that fault reactivation is not a localized phenomenon but arises from a combination of factors, including mining face configuration, intrinsic fault plane properties, and dynamic interactions between the fault and surrounding rock masses. Through high-resolution numerical simulations, we track the temporal evolution of stress redistribution and strata displacement as the mining front progresses along fault zones. The findings underscore that the progressive movement of overlying rock is the dominant driver of fault reactivation. These insights advance our understanding of mining-induced fault instability and offer a theoretical basis for mitigating fault slip-related rockbursts in deep mining environments.